A review of catalytic conversion of coal tar value-added chemicals at the molecular level based on first principles

Coal tar (CT), a byproduct of coal pyrolysis, is a valuable source of chemicals not producible by the petrochemical industry. However, its complex composition and lack of effective conversion principles pose significant challenges for value-added utilization. This review focuses on the CT non-hydrogenation catalytic (CTC) and CT hydrogenation catalytic (CTHC) technologies for typical model compounds, fractions and full range of CT on a molecular level, providing an overview of the various catalysts and modification methods employed in CT and its precursor, to light aromatics (BTEXN) by CTC, high-energy-density fuels (HEDFs, Jet/Aerospace fuel) and chemicals (light aromatics and lubricants) by CTHC, and to fuels (gasoline and diesel) by hydrocracking. Additionally, this paper summarizes and elucidates the insights into the correlations between CT composition, catalyst structure, and product distribution. Combined with the corresponding achievements and research experience of this research team, the problems existing in the process of CTC and CTHC were pointed out, and the first principles of "point (single model compound)-line (mixed model compounds)-surface (group components/ fractions)-body (CT)" for the step-by-step analysis and conversion of CT catalytic mechanism and value-added process were proposed. These advancements offer promising solutions for improving the quality and energy density of CT-derived products.